Nowadays, great changes have taken place in electronic products because of the rapid development of technology. Touch electronic products become more and more popular ever since they appeared in the market. Touch electronic products save space and are easy to carry. Further more, touch electronic products are comfortable and convenient to use, because they can be directly operated by using a finger or a touch pen. Popular products such as PDAs, touch mobile phones, portable computers and so on are increasingly relying on touch technology, and it is apparent that touch electronic devices will be widely applied in many fields.
Because capacitive touch devices can stand wear and tear, enjoy long life and have advantages in system function and in reducing light losses, they are being well-accepted by the market and many kinds of capacitive touch devices have been created.
The operation principle of a capacitive touch device is to use a controller chip to sense changes in capacitance in the capacitors of the touch panel and determine the position and the gesture of the touch object, such as a finger. During the touch sensing process, the horizontal electrode array and the vertical electrode array of the touch panel are detected separately, and horizontal coordinates and vertical coordinates are determined according to the change in capacitance before and after the occurrence of a touch. Then, the horizontal and vertical coordinates are combined to form coordinates of the XY plane. The detecting method above is in fact equivalent to first projecting the touch points on the touch panel on the X-axis and the Y-axis respectively, then calculating the coordinates in the X direction and Y direction, and finally combining these X and Y coordinates to form the touch points' coordinates in the XY plane. This detecting method, unfortunately, can only detect a single object and cannot achieve the detection of multiple objects on the touch device.